Matic, 25, moved to Portugal as part of the deal that brought defender David Luiz to London in 2011, having made three Premier League appearances for Chelsea.

But the Blues have since kept tabs on the Serbia international -- also reported to be a target for Real Madrid -- and it is thought they would have to pay around £15 million to bring him back to London.

Metro quoted him as saying: "I would probably like to stay another year with Benfica, but if somebody like Mourinho wanted to bring me back to London it would be difficult to turn down.

"It would be a great chance to prove that I can play in the Premier League."